Many people in today's world engage in various forms of wireless communication via various wireless networks using various wireless-communication devices (WCDs), which are often also or instead referred to using terms such as access terminals, user equipment, mobile radios, mobile stations, mobile devices, and the like. Some example types of commonly used WCDs include cell phones, smartphones, tablets, laptops, mobile Wi-Fi hotspots, and the like.
WCDs are typically equipped, programmed, and configured to be able to engage in one or more types of wireless communication, according to one or more wireless-communication protocols. In a typical arrangement, a WCD includes one or more wireless-communication chipsets for each type of wireless communication in which that device is able to engage; moreover, some chipsets are capable of engaging in multiple types of wireless communication. In general, a given chipset is typically engineered to be compatible with one or more wireless-communication bands, each of which is typically associated with a given wireless network. Some chipsets are compatible with a set of bands that are all associated with the same network, while other chipsets are compatible with a set of bands that includes at least two different bands that are respectively associated with two different networks.
It is often the case that, in order to gain access to a given wireless network using a given chipset, that chipset includes or is connected by circuitry to a security credential for authenticating on that network. One common example form that such a security credential can take is that of a subscriber identity module (SIM), often referred to as a SIM card. Some wireless networks are commercial in nature, and associated WCDs are correspondingly equipped with compatible commercial SIMs; other wireless networks are operated by and/or for public-safety devices, and associated WCDs are correspondingly equipped with compatible public-safety SIMs. And certainly there are other types of SIMs as well.
Moreover, in the context of a WCD being compatible with multiple different wireless networks, it often occurs, for any one of a variety of possible reasons, that the WCD either makes its own determination or receives a (local or remote) command to switch from obtaining wireless service from one network on one band to obtaining wireless service from a different network on a different band. One common example of such a transition is known in the art as roaming. Some example reasons for a given transition from one network to another include loss of coverage and/or service from the first network, mobility of the WCD, relative cost of operating on the networks, network load-balancing considerations, the WCD being “homed” on a given network and not on another, and the like. Accordingly, there is a need for the present methods and systems for flexible fast network switching.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments. Moreover, the apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.